Modular system for improving electro-metallurgical processes

ABSTRACT

A modular system for improving electro-metallurgical processes comprising a nucleus formed by upper and lower rectangular frames, the nucleus. At least one cathode guide is attached to at least one of longitudinal beams. The at least one cathode guide is operable to keep positive ions from reaching border or edge of the cathode. At least one anode guide is provided.

BACKGROUND

The industrial obtainment of high purity metals such as copper, nickel,zinc and others is carried out mostly by electrolytic deposits from acidor alkaline water solutions of the respective metals. Whether the metalis obtained from its solutions using insoluble anodes or by dissolvinganodes of the metal itself, stainless steel cathodes, also known aspermanent cathodes, are vastly used through out these industries.

Although the use of permanent cathodes has solved some processingissues; because the metal is also deposited on their vertical and lowerhorizontal edges the dislodging of the metal deposited presents severedifficulties. Moreover, since this step is done mechanically byintroducing knives between the metal deposited and the stainless steelplate, irregularities on the edges and scratches and deformations on thefaces of the cathodes occur. All this means that the stainless steelcathodes must be straightened, re-polished and on occasion replaced withthe resulting associated costs.

To avoid the electro-deposition of the metal on the edges of thecathodes, some have resorted to covering them with plastic strips tokeep them from having contact with the electrolyte. Although the stripsare pressure locked onto the sides of the cathodes, the fact that theelectrolysis is carried out at temperatures of about 50° Celsius causesthe strips to expand and deform. These deformations result in animperfect seal of the borders of the cathodes that allow large nodulesof metal to be electro-deposited on the exposed zones. These nodules addanother degree of difficulty to the removal of the plastic strips aswell as to the metal deposited. When this occur the metal nodules haveto be hammered off to be removed. During this operation the lower endsof the strips are destroyed, making their replacement necessary with theresulting associated costs.

Attempts have also been made to cover the sides of the cathodes that aresubmerged in electrolyte with a half-frame, shaped like a letter U, ofthe same metal that is being obtained, so as to form a screen that keepsthe deposits from forming on the borders. Although it is true that thisscreen reduces the amount deposited, it does not solve the entireproblem.

In an attempt to resolve this weakness, an effort was made to connectthe half-frame to an external source of radio frequency, which wouldsolve the problem. Nevertheless, the fact that the half-frame is made ofmetal and that it is connected to the same potential of the cathode,causes the metal to deposit also on the outside of the half-frame,increasing its thickness, and forcing its reconditioning or replacementafter a few production cycles.

In addition to the problems mentioned, because the anodes and cathodesare suspended freely within the cell, when the anodes and cathodesoscillate occasional short-circuits are produced that diminish thecurrent efficiency of the operation and force the re-processing of thedamaged products and the repairing or replacement of the anodes andcathodes.

All these problems increase production costs and lower the quality ofthe cathodes produced having detrimental business consequences.

Recently, a holding structure of an insulating material was designed, towhich energizable slots were attached. These slots serve as verticalguides for the sides of the cathodes so they have been named “cathodeguides”. These slots can be energized with a DC current and a highfrequency voltage potential to control the cathode peripheral depositand eliminate the use of plastic strips to solve this problem.

Another problem associated to the operation in the electro-metallurgicalprocesses is the formation of acid fog that cause health problems amongthe workers and damages to the structures of buildings, equipment andinstruments. Efforts have been made to try and solve this problem byeither inhibiting its formation by the introduction of radio frequenciesor preventing its propagation outside the cell by the application ofair-curtains to condense the vapors present in the fog and return thecondensates to the electrolyte, the use of extraction hoods, surfactantsto reduce the surface tension of the solution and minimize electrolytepulling, plastic spheres to reduce the electrolyte pulling.

SUMMARY

To overcome some of the problems mentioned above and to realize some ofthe discussed advantages, there is provided a modular system forimproving electro-metallurgical processes comprising a nucleus formed byupper and lower rectangular frames, the nucleus. At least one cathodeguide is attached to at least one of longitudinal beams. The at leastone cathode guide is operable to keep positive ions from reaching borderor edge of the cathode. At least one anode guide is provided.

Another aspect of the disclosed teachings is a use of the systemdescribed above in a treatment of liquid waste or electroplating.

DESCRIPTION OF THE DRAWINGS

The above objectives and advantages of the present invention will becomemore apparent by describing in detail embodiments thereof with referenceto the attached drawings in which:

FIG. 01.a is an isometric view of a subassembly of two cathode guideprofiles according to an exemplary embodiment of the present invention.

FIG. 01 shows an enlarged isometric view of the upper part of asubassembly of two cathode guide profiles according to an exemplaryembodiment of the present invention.

FIG. 02.a shows an isometric view of an anode guide profile according toan exemplary embodiment of the present invention.

FIG. 02 shows an enlarged isometric view of the upper part of an anodeguide profile according to an exemplary embodiment of the presentinvention.

FIG. 03 shows an isometric view of the Nucleus of the Modular System forImproving Electro-metallurgical Processes according to an exemplaryembodiment of the present invention.

FIG. 04 shows an isometric view of a Horizontal Spacer according to anexemplary embodiment of the present invention.

FIG. 05 a-b show an isometric view of the Cathode type Nucleus Holderaccording to an exemplary embodiment of the present invention.

FIG. 06 shows an isometric view of the Anode Bracket type Nucleus Holderaccording to an exemplary embodiment of the present invention.

FIG. 07 shows an isometric view of the Head-type Nucleus Holderaccording to an exemplary embodiment of the present invention.

FIG. 08 shows an isometric view of the Nucleus positioned inside thecell, during the anode and cathode loading process according to anexemplary embodiment of the present invention.

FIG. 09 shows an isometric view of the Nucleus, with the cathode-typeNucleus holders, anode bracket type nucleus holders and head typenucleus holders installed in position according to an exemplaryembodiment of the present invention.

The numbers that indicate the details in the different Figures, have thefollowing meaning:

-   -   1. Cathode aligner    -   2. Cathode guide (in versions to insert a bare cathode or one        with plastic stripping).    -   3. Shock absorber.    -   4. Anode aligner.    -   5. Anode guide.    -   6. Left longitudinal holding beam of the Upper Frame of the        Nucleus.    -   7. Rear upper holder of the Upper Frame of the Nucleus.    -   8. Right rear corner pillar that joins the Upper and Lower        Frames of the Nucleus.    -   9. Cathode guide.    -   10. Resting component of the Nucleus on the floor of the        Electrolytic Cell.    -   11. Right longitudinal lower holding beam of the Nucleus lower        Frame.    -   12. Right central pillar that joins the Nucleus Upper and Lower        Frames.    -   13. Right diagonal of the Nucleus Frontal head.    -   14. Right front corner pillar that joins the Nucleus Upper and        Lower Frames.    -   15. Right front transversal beam of the Nucleus Head of the        lower Frame.    -   16. Left diagonal of the Nucleus Frontal head.    -   17. Intermediate front transversal reinforcement beam of the        Nucleus Frontal Head.    -   18. Upper frontal transversal beam of the Nucleus Frontal Head.    -   19. Right longitudinal holding beam of the Nucleus Upper Frame.    -   20. Anode housing.    -   21. Cathode housing.    -   22. Diagonal lateral stiffener.    -   23. Window for crane coupling.    -   24. Coupling angle to the longitudinal Holding Beam of the        Nucleus Upper Frame.    -   25. Bar of the Nucleus Holder, cathode type.    -   26. Anode-type Bracket of the Nucleus Holder.    -   27. Cube for bolting to the longitudinal support beam of the        Nucleus Upper Frame.    -   28. Support to the upper head of the electrolytic cell masonry.    -   29. Tip that is fastened to the Nucleus.    -   30. Cathode    -   31. Anode

Description of the Modular System for Improving Electro-metallurgicalProcesses

An exemplary embodiment is of a modular system for improvingelectro-metallurgical processes is described in relation to FIGS. 1-8.It is structured as of a Fundamental Module, known as a Nucleus,represented in FIG. 03, to which other Modules or elements can becoupled or uncoupled to solve electro-metallurgical process problemssuch as those described previously in the Background section.

In the exemplary embodiment, the Nucleus of FIG. 03 is made up of anupper Frame formed by the left (6) and right (19) longitudinal holdingbeams and by the front or frontal (18) and rear (7) transversalsupports, a lower Frame formed by the lower right longitudinal holdingbeams (11) and another equivalent one on the left side, and the lowerbeams of the Frontal heads (15) and their equivalent in the rear head.Both Frames are joined by means of right hand corner pillars (8) and(14) and their equivalent on the left side, one or more IntermediatePillars such as that designated with the number (12) and one or morediagonals on the right side like the one designated with the number (22)and its equivalent on the left side. In both heads there are diagonalslike those designated as (13) and (16) in the frontal head and otherequivalent ones in the rear head. Optionally and depending on thedimensions of the Nucleus, reinforcement Beams can be incorporated likethe one designated with number (17), both in the frontal and in the rearhead. Optionally, in the lower longitudinal beams (11) and theiropposite number on the left side, there are elements for resting on thefloor of the cell, such as that designated with the number (10).

Depending on the problem that needs to be solved, independent moduleswith specific purposes can be attached to work in conjunction with theNucleus, which is why it has been designed to be compatible with thefollowing modules:

-   -   Compatible with Module that eliminates borders or plastic        strips.    -   Compatible with Module for installation in a wet or dry cell.    -   Compatible with hanging installation or installation resting on        the bottom of the cell.    -   Compatible with acid fog abatement module.    -   Compatible with module for transversal circulation of        electrolyte,        Plastic Stripping Eliminator Module.

In this exemplary embodiment, the plastic stripping eliminator module ismade up of a set of cathode guides (2) and optionally a set of anodeguides (5) and/or a Spacer Module like the one shown in FIG. 04. Boththe cathode guides (2) as well as the anode guides (5) can be installed,optionally, with their corresponding cathode aligners (1) and anodealigners (4), which are fixed in a vertical position on both interiorsides of the Nucleus. The transversal profile of the cathode guide canbe shaped like an omega, or a U and/or V, its length being greater thanthe length of the cathode immersed in the electrolyte, the width of thechannel of the omega or of the U and/or of the V profile must beslightly greater than the thickness of the cathode in use. The cathodeguides must be installed in such a way that the lower corners of thecathode, once the cathode is positioned in the cell, they are totallycovered by the cathode guide. Optionally, the cathode guide can bereinforced with a shock absorber (3). The transversal profile of theanode guide (5) corresponds to a channel whose distance between opposingfaces must be slightly greater than the thickness of the anode that willbe employed. The aligners have the shape of a truncated cone or invertedtruncated pyramid, open towards the center of the cell, and theirfunction is to act as a funnel to facilitate the introduction of thecathodes and anodes respectively into the cell. Depending on theapplication, the cathode guides (1) may be used only with the anodeguides (5), with or without aligners or the cathode guides only with ahorizontal spacer module like the one in FIG. 04, or the cathode guidestogether with the anode guides and the horizontal spacer module.

Module for Installation in a Wet or in a Dry Cell.

The installation in a Wet or in a Dry Cell can be executed by attachingelements to the Nucleus that make it easier to lift and transfer it withthe help of the traveling crane of the EW plant. These elements can belocated in positions occupied by cathodes, by anodes or at the ends ofthe Nucleus. The version known as Cathode Type Nucleus Holderrepresented in FIG. 05 a-b, consists of a bar (25) with two windows forthe Crane hooks (23) and two coupling angles to be attached to thelongitudinal support beam of the Upper Frame of the Nucleus (24). Two ormore of these cathode type Nucleus holders attached in positionsnormally occupied by cathodes are needed. The version known asAnode-type Bracket of the Nucleus Holder, represented in FIG. 06,consists of a Holder (26) joined to a Cube (27), to be attached by meansof a bolt or other system, in two or more anode positions, in each oneof the longitudinal support beams of the upper frame of the Nucleus. Theversion known as Head-type Nucleus Holder, represented in FIG. 07,consists of one end that rests on the electrolytic cell upper headmasonry (28) and one end that is attached to the Nucleus (29). Theseholding systems can be used independently one at a time or in anycombination thereof.

Likewise, they can remain installed permanently or be installed fortheir use and removed later. By using the plant's traveling crane, theseholders make it possible to lift, introduce and/or remove the Nucleusfrom the cell with all the cathodes and anodes in position, whether thecell is empty or full of electrolyte.

Module for a Hanging Installation or One Resting on the Bottom of theCell.

Depending on the type of operation that one wishes to carry out, it mayor may not be convenient to rest the Nucleus on the bottom of the cell.When, for any reason, one wishes to avoid the resting on the bottom ofthe cell, the Head Assembly Support Module, consisting of four supportslike the one shown in FIG. 07 may be installed. These supports areinstalled at the ends of the longitudinal support beams of the upperframe of the Nucleus (6) and (19), as shown in FIG. 09, and theirprojecting head support ends of the masonry electrolytic cell (28) arelocated directly over the heads of the cell itself, preventing the lowerframe of the Nucleus from resting on the bottom of the cell.

Acid Fog Abatement Modules.

As mentioned previously, there are at least two systems patented inChile to control the acid fog. The Modular System for ImprovingElectro-Metallurgical Processes of this Invention has been designed tomake it compatible with the utilization of either of them.

Electrolyte Transversal Circulation Module.

A module is being developed to facilitate the transversal circulation ofthe electrolyte. The exemplary embodiments of the disclosed system iswith such a module.

EXAMPLE OF APPLICATION

It order to experimentally verify the results of the application of theModular System for Improving Electro-Metallurgical Processes, andwithout this meaning a limiting of the System's applicability, a pilotelectrolytic cell built with fiberglass reinforced plastic, measuring 40cm wide by 55 cm long and 35 cm deep was used to simulate an IndustrialElectro-Winning Plant to obtain copper was made at a laboratory forwhich a pilot electrolytic cell was used, built of plastic reinforcedwith fiberglass, measuring 40 cm wide by 55 cm long and 35 cm deep.

The Nucleus of the Modular System for Improving Electro-MetallurgicalProcesses, similar to the one represented in FIG. 03, was introducedinto this cell. The general dimensions of the Nucleus that wasintroduced into the Electrolytic Cell are 35 cm wide by 50 cm long and35 cm high.

In the Nucleus used, a module of five cathode guides (2) was coupled toeach side on the left (6) and right (19) longitudinal support beams andon the lower right longitudinal support beam (11) and its lowerequivalent on the left side. All this with its corresponding cathodealigners (1). Next, a Horizontal Spacer, similar to the one shown inFIG. 04, was coupled at the bottom of the cell, with six pairs of anodehousing (20) and five pairs of cathode housing (21). The distancebetween anodes as well as that between cathodes was fixed at 100 mm, thesame one used in the simulated Industrial Plant.

Then the five stainless steel cathodes measuring 20 cm wide by 24 cmhigh by 2 mm thick, mounted on a copper cathodic bar having a diameterof 19 mm and a length of 40 cm, were introduced one by one; then sixlead cathodes measuring 14.3 cm wide by 23.5 cm high by 2 mm thick,mounted on a copper anodic bar having the same dimensions as thecathodic bar, were introduced.

Once the cathodes and anodes had been loaded, the cell was filled withcopper sulfate electrolyte, having a composition equivalent to that ofthe simulated Industrial Plant, and the deposit was started at apotential of 2.6 Volts between anode and cathode, employing a currentdensity of 300 Amperes per square meter.

At the end of the operating cycle, the following was observed:

1. Both the chemical as well as the physical quality of the cathodeimproves. With regard to the chemical quality, a smaller content ofLead, Sulfur and Iron is reflected. On the other hand, the occlusion ofcopper sulfate on the borders of the deposit is eliminated because theModular System for Improving Electro-Metallurgical Processes does notuse plastic strip. With regard to the physical quality, by ensuring theparallelism between anodes and cathodes, the short-circuits areeliminated, the grain of the deposit is homogenized and refined, nocopper ribbons were observed in any of edges of the copper cathode and aperfectly linear upper border of the cathodic deposit was obtained.

2. Current efficiency increases. How to take advantage of this benefitdepends on the metal availability in the electrolyte. That is, the metalproduction can be increased, the electric power consumption can bereduced, or the harvesting cycle can be shortened.

3. Improves the increase of current density. This benefit is the directresult of confining the cathodes and anodes inside the Modular Systemfor Improving Electro-Metallurgical Processes, that allows, according tothe metal content in the electrolyte and without an additionalinvestment, either increase the plant capacity, shorten the harvestcycle or reduce the number of cathodes per cell.

4. It provides an operational path for breaking the paradigm of distancebetween cathode and anode. This benefit is the direct result of theconfinement of cathodes and anodes within the Modular System forImproving Electro-Metallurgical Processes that permits, according to theavailability of copper and without an additional investment, either toincrease the plant capacity by increasing the number of cathodes percell, to shorten the harvest cycle, or reduce the number of cells.

5. Equitable distribution of the current through the cathodes. Thisbenefit is translated into a lower variability of the currentefficiency, of the weight of the cathodes, and of the chemical andphysical quality of the cathodes.

6. Operational Improvements. The operational improvements includemultiple benefits that arise from the absence of jacketed cathodes,absence of short-circuits and the ease with which the cathodes depositedcan be loosened from the stainless cathode substrates with the ModularSystem for Improving Electro-Metallurgical Processes. The most importantof these are: greater availability of equipment, reduction of humanresources and reduction of raw materials costs. First, the factors thataffect the greater availability of equipment are: 100% detaching inpeeling machine, reduction of stripping frequency, increased useful lifeof the cathode, the anode and the cell, and increased availability ofthe traveling crane.

Second, the reduction of the Human Resources corresponds to the reducedsupervision of short-circuits, manual detachment of plates andrectification of short-circuited cathodes.

Finally, the cost reduction associated to other supplies used in the EWprocess relates to the elimination of plastic borders, the eliminationof cathode/anode spacers and the consumption reduction of chemicalreagents.

Other modifications and variations to the invention will be apparent tothose skilled in the art from the foregoing disclosure and teachings.Thus, while only certain embodiments of the invention have beenspecifically described herein, it will be apparent that numerousmodifications may be made thereto without departing from the spirit andscope of the invention.

1. A modular system for improving electro-metallurgical processescomprising: a nucleus formed by upper and lower rectangular frames, thenucleus; at least one cathode guide being attached to at least one oflongitudinal beams, the at least one cathode guide being operable tokeep positive ions from reaching border or edge of the cathode; and atleast one anode guide.
 2. The modular system of claim 1, wherein thenucleus is linked by at least one corner pillar.
 3. The modular systemof claim 1, wherein the nucleus is linked by at least one centralpillar.
 4. The modular system of claim 1, further comprising at leastone diagonal reinforcement.
 5. The modular system of claim 1, whereinthe cathode guide has an omega type or u, or v cross-sectional shape. 6.The modular system of claim 1, wherein the cathode guide is operable tohave a bare cathode inserted therein.
 7. The modular system of claim 1,wherein the cathode guide is operable to have a cathode with plasticstripping on a periphery of the cathode inserted therein.
 8. The modularsystem of claim 1, wherein the cathode guide has a cathode alignerattached thereto.
 9. The modular system of claim 1, wherein the anodeguide has an anode aligner attached thereto.
 10. The modular system ofclaim 1, further comprising an anode space module.
 11. The modularsystem of claim 1, further comprising at least two sets of cathode typesupport bars.
 12. The modular system of claim 1, further comprising atleast four sets of bracket anode supports.
 13. The modular system ofclaim 1, further comprising at least a set of four head supports. 14.The modular system of claim 1 comprising at least two cathode guidesfacing each other and joined at their lower ends by means of a profile.15. The modular system of claim 1 further comprising an acid fogabatement module.
 16. The modular system of claim 1 further comprisingfurther comprising an electrolyte transversal circulation module. 17.The modular system of claim 1 operable to be used in a treatment ofliquid industrial waste.
 18. The modular system of claim 1 operable tobe used in electroplating.
 19. A use of the system of claim 1 in atreatment of liquid waste or electroplating.